The present invention concerns hydraulic systems for various types of equipment and more particularly to a system for disabling the hydraulic system of a piece of earth moving equipment to prevent unauthorized use or theft of the equipment.
Occurring with considerable frequency is the theft of heavy equipment such as that used at roadway and building construction sites which is left unattended when not in use. The amount of heavy construction equipment lost to theft is in the realm of several millions of dollars each year to contractors and resulting in losses, high insurance premiums as well as the inconvenience and lost time in replacing equipment lost by theft.
Typically construction vehicles such as front end loaders, track equipped tractors, backhoes, graders, etc., have ignition systems which may be circumvented to permit starting without a key which has contributed to the common theft and/or vandalism of same. Once started, typically all hydraulic system components may be operated with no provision made in the vehicles for disabling of the vehicle hydraulic system as a secondary theft prevention measure.
In the prior art, U.S. Pat. Nos. 1,062,154 and 1,384,697 show fuel valves with provision made for remotely locking same closed; U.S. Pat. No. 1,273,740 discloses a manifold lock; U.S. Pat. No. 1,316,592 shows a remote lock for a vehicle vacuum system; U.S. Pat. No. 3,090,218 shows a pipe valve and lock combination; U.S. Pat. No. 3,170,579 shows a hydraulic console locking apparatus; U.S. Pat. Nos. 1,524,904 and 1,153,189 show key actuated, fluid valves.